Part 2 - Dose Expansion will be conducted pending safety results of Part 1 to provide guidance regarding the recommended phase 2 dose (RP2D). Subjects will be treated and assessed as outlined in Part 1 above. If 0 out of 3 subjects, or 1 out of 6 subjects, experience dose limiting toxicities (DLTs) at the 5 x 10^9 dose level in Part 1, additional subjects to a total of 10 will be recruited to this dose level in Part 2. Similarly, if 0 out of 3 subjects, or 1 out of 6 subjects, experience DLTs at the 8 x 10^9 dose level in Part 1, additional subjects to a total of 10 will be recruited to this dose level in Part 2. If both dose levels are tolerated, a total of 10 subjects per dose level will be enrolled.